1. Field of the Invention
The present invention relates to a mechanism or device for holding a disk-like information recording medium in a rotationally driving apparatus. The disk information recording medium includes a disk medium, such as an MO, PD, CD, CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-R, DVD-RW, DVD-RAM, for optically reproducing and recording information, and is simply referred to as xe2x80x9cdiskxe2x80x9d herein. Apparatuses for reproducing information from and recording information on such a disk, including a CD-ROM drive and DVD drive, are herein referred to as xe2x80x9cdisk drive apparatusxe2x80x9d. In particular, the invention relates to a mechanism used in a disk drive apparatus for clamping a disk on a turntable.
2. Description of the Related Art
In recent years, disk drive apparatuses have become increasingly small and thin and are incorporated in thin portable personal computers. As the disk drive apparatuses are downsized, more and more small, thin notebook computers contain such disk drive apparatuses. In addition, the volume of software used in computers and the number of inexpensive CD-ROMs distributed as media attached to magazines are also increased. These factors also necessitate the inclusion of the disk drive apparatus in the computer.
A clamp mechanism of a conventional disk drive apparatus will be described below. The following three systems have been conventionally used.
One is a disk-self-insert/eject (clamp) system in which a user holds a disk and directly places it on a turntable, which is a component of an optical pickup unit.
A second one is a tray system. In this system, a tray is ejected from a disk drive apparatus, a disk is placed on the tray, the tray is retracted into the apparatus, and then the disk is lowered onto a turntable or the entire pickup unit rises to place the disk on the turntable. Then, a cylindrical member called xe2x80x9cclamperxe2x80x9d holds the disk to the turntable from the topside thereof with magnetic attraction.
A third one is a system in which a disk contained in a disk case called xe2x80x9ccaddyxe2x80x9d is inserted into a disk drive apparatus. The disk is held on a turntable by a clamp member provided on the top of the caddy, with the aid of an attractive force of a magnet provided in the turntable.
A new system called xe2x80x9cslot loadingxe2x80x9d has been proposed. In this system, when a disk is inserted into a certain position of a disk drive apparatus through a slit called xe2x80x9cfront bezelxe2x80x9d formed in the front panel of the disk drive apparatus, the disk is automatically retracted onto a turntable in the apparatus. This system is easy to operate, highly dust-resistant because of its small disk outlet, and unsusceptible to harmful effect such as static electricity from a human body. This system is used in an on-vehicle CD player, MD player, and portable MD device.
However, such system is not widely used in other applications such as home audio or CD-ROM drive apparatuses. Because, in order to adopt the slot loading system, the apparatus needs to have a space for retracting a disk. That is, if the slot loading system is realized by using the same clamp mechanism as that used in a conventional disk drive apparatus, the thickness of the entire disk drive apparatus increases by an amount or size of the above-described space.
The industrial standard thickness of a disk drive apparatus contained in a small, thin notebook computer is 12.7 mm. Therefore, implementing a slot-loading disk apparatus requires a completely new medium attaching device.
An object of the present invention is to provide a medium attaching device capable of holding a disk with a considerably thin thickness as compared with the prior-art device.
It is another object of the invention to provide a slot-loading disk drive apparatus using such medium attaching device and having a thickness of 12.7 mm or less.
A clamp mechanism according to the invention is thin and capable of automatically holding a disk when the disk is placed in a disk drive apparatus. The clamp mechanism is incorporated in a spindle motor of the disk drive apparatus to realize an ultra-thin slot-loading disk drive apparatus having a thickness of 12.7 mm, which is a typical thickness of the predominant CD-ROM drive apparatus incorporated in recent notebook computers.